Capacitance multiplier (CB7803E)

We found this circuit in an old Popular Electronics. The circuit can be applied to other operational amplifiers.

Debouncer (CB20546E)
This anti-ringing circuit was found in an English documentation from 1996. The integrated circuit is...
Higher gain stage (CB25057E)
The figure shows how to increase the gain of the amplifier stage of the previous circuit. The...
Voltage Controlled Function Generator (CB18882E)
This circuit uses unusual operational amplifiers, but equivalents can be tried. FETs can also be...